Traffic control system



June 13, 1967 N. DER

TRAFFIC CONTROL SYSTEM Filed Jan. 11, 1965 REMOTE McHoLns DE@ rroeA/EYS.

United States Patent O 3,325,782 TRAFFIC CONTROL SYSTEM Nicholas Der, 1735 N. Kingsley Drive, Los Angeles, Calif. 90927 Filed Jan. 11, 1965, Ser. No. 424,771 9 Claims. (Cl. 340-31) This invention relates to road trai-lic control apparatus.

For a variety of reasons, drivers enter freeways through ott-ramps rather than on-ramps, all too often with fatal consequences. It has been proposed to utilize slanted spikes that, depending upon the direction of travel, either move flush with the road surface or cause a tire puncture. Such devices, however, are psychological hazards to drivers proceeding in the correct direction.

The primary object of ythis invention is to provide a system for controlling the direction of tra'ic ow in which no obstacle whatsoever projects from the road surface except when traic ow is in the reverse direction. In order to accomplish this function, I provide a movable mounting for the spikes whereby the spikes are normally positioned beneath the road surface, together with a logic circuit operated by pressure switches in the road to elevate the spikes upon attempted improper entry.

Another object of this invention is to .provide a safety system of this character operable in a foolproof manner where multi-lane off-ramps are provided.

Another object of this invention is to provide a simple logical circuit for accomplishing the foregoing objects.

This invention possesses many -other advantages, and has other objects which may be made more clearly apparent from a consideration of several embodiments of the invention. For this purpose, there yare shown a few forms in the drawings accompanying and forming part of the present specification, and which drawings, unless described as diagrammatic, or unless as otherwise indicated, are true scale. These forms will now be described in detail, illustrating the general principles of the invention; but it is -to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a plan view of a portion of a typical freeway olf-ramp.

FIG. 2 is an enlarged transverse sectional view taken along a plane corresponding to line 2-2 of FIG. 1; and

FIGS. 3 and 4 are circuit diagrams for single lane and multi-lane systems respectively.

ln FIG. l there is illustrated a freeway generally indicated by the reference character 1 and an olf-ramp 2 leading Ito a city street 3 or the like. The off-ramp 2 is intended only for traiiic moving from the freeway 1 to the street 3. Despite the fact that signs may be posted adjacent Vto the street side of the off-ramp 2, persons may unintentionally or otherwise enter the Off-ramp 2 and thus enter the freeway 1 from the wrong direction with possibly serious consequences.

In order to prevent this, I provide a barrier 4 normally recessed beneath the level of the oli-ramp.

The barried 4 (FIG. 2) includes an arm S pivoted on a bracket 6 for angular movement about a horizontal axis transverse to the off-ramp and beneath its surface. One end of the arm pivotally mounts a cylindrical support 7 forangular movement about its own axis. Suitable yielding means, such as eccentric weights or springs (not shown) bias the support to move angularly in a counterclockwise direction. A stop 8 limi-ts this movement.

Mounted on the support are a series of spikes 9 designed to puncture and rip any vehicle tire. The spikes have barbs 10 whereby even puncture-proof tires are effectively mutilated to the point where they cannot hold air.

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The spikes 9 are movable upwardly by a counterweight 11 and a motor or solenoid 12 to the phantom line position shown in FIG. 2. In this position the spikes 9 are projected through slots 13 in a cover plate 14 and slant toward the street side of the olf-ramp. Should a vehicle move in the direction of the arrow 15, the tires will be punc-tured, the reaction between the tire and the spike being ineffective to rotate the barrier downwardly. However, when thrust is imposed upon the spikes 9 from the opposite side as by a car moving in the correct direction, and indicated by the arrow 16, the barrier depresses. The spikes may also be individually spring mounted so that only the spikes engaged by the tires depress. In this case t-he support 7 would be fixed to the arm 5.

The barrier 4 however, is elevated and thus conditioned for operation only by travel of a car in the reverse direction as indicated by the arrow 16.

The system may be used with a single or multi-lane offramp. A detailed description of a single lane system will assist in the understanding of the multi-lane system'.

Hence, for the present, let it be assumed that the off-ramp comprises only one lane.

In order to sense reverse movement of a car or other vehicle, three switches S1, S3 and S2 (FIG. 1) are provided that may be of a conventional type commonly used for control of signal intervals. The switch S1 is normally closed, while switches S2 and S3 are normally open. These pressure switches are likewise embedded in the surface of the road. The iirst switch S1 may be located fairly close to the street. The spacing may be of the order of one or two feet -between switches S1, S2 and S2 yand S3. If the pressure switches are engaged in the sequence S1, S2 and S3 the barrier will be elevated. However, if the switches are engaged in the reverse, S3, S2 and S1, the barrier will not be elevated. After the switches are engaged in the sequence S1, S2 and S3 a series of warning alarms W will be operated and for the purpose of informing the drivers leaving the freeway of possible danger, and also for the purpose of informing the wrong-way driver that he will encounter a dangerous barrier or so feet ahead. The warning W (visual and/or audible) may be situated in any desired position. Simultaneously with the operation of the alarms the motor 12. is operated. If desired a signal alarm A may be also transmitted to the situable police or highway agency.

For these purposes a logic circuit shown in FIG. 3 is provided. It includes two relays R2 and R3, both having but a single set of normally open contacts R2A and RaA. The motor 12 designated as M is shown along with the warning alarms W and the signal alarm A. A key operated switch K may be incorporated for purposes of disabling the system, as for example when ambulances or other service vehicles must of necessity enter an oif-ramp of a freeway.

The switch S1 preferably includestwo serial p arts, respectively located at opposite sides of the structure so that no matter where the pressure switch is engaged one or the other of the switch elements will be opened to achieve the desired function hereinafter to be described. Similarly the switches S2 and S3 include twoelements.

In order to operate the motor M and the alarm A and the warning system W use is made of a suitable commercially available source cooperable with terminals T1 and T2. One side of the switch S2 as at the terminals T3 is normally connected by line L1 to the source terminal T1 via the key switch K and the normally closed switch S1. Assume that a wrong-way driver enters the olf-ramp. The switch S2 will be operated as by the passage of the front wheels of the vehicle and the line L1 will be connected to a line L2.v This causes energization of the relay R2 through a circuit as follows: Terminal T1, Switches K and S1, line L1, switch S2, lead L2, relay R2 back to the return lead L3 and the terminal T2. When the relay R2 is energized contacts R2A are closed and a holding circuit operates. The holding contacts connect the leads L1 and L2 together independently of the switch S2, thus the contacts R2A parallel the switch S2. Thus even though the switch S2 may be only momentarily engaged as the forward wheel of the vehicle moves in the improper direction, the lead L2 remains connected with the source terminal T1.

Thereafter the front wheels of the vehicle engage the switch S3. VWhen the switch S3 is engaged the lead L4 is connected to the lead L2 and the motor M, warning system W and signal alarm A are operated. The relay R3 holds this condition. Thus relay R3 is simultaneously energized by switch S3, and holding contacts R3A engage to parallel the switch S3. Accordingly the barrier 4 is raised, warning system ashes and/or sounds and the alarm is transmitted.

Depending upon the number of wheels on the vehicle the sequence just described is repeated. The wheels of the second set interrupts the holding circuits as they pass switch S1; but these wheels will also activate the system by engaging switches S2 and S3. The final wheels of the vehicle (whether the second, third, or fourth set) produce the sequence of the events described, resulting in ultimate operation.

If the driver heeds the warning lights he will back down and engage the switches S3, S2 and S1 in reverse sequence. As he engages the switch S3 nothing happens since the holding contacts R3A are operative. As he engages the switch S2 nothing happens because the holding contacts R2A are operative, but iinally as he engages the switch S1 the holding circuits are interrupted and the system is reset. The rearwardmost wheels reset the system.

The remaining wheels operate in the same manner as wheels of a vehicle moving in a proper direction, which Vwill now be described. The relays R2 and R3 are normally.

not energized. Hence a driver proceeding in the correct direction does not cause operation of the barrier, etc. Thus assuming the relays R2 and R3 are not energized the vehicle engages the switch S3 which is ineffective to energize relay R3 because the relay R2 is de-energized. Thereafter as the driver proceeds he engages the switch S2 which results in momentary operation of the relay R2, but he immediately thereafter engages the switch S1 which interrupts the holding circuit. Thus the relay R3 is never energized when the vehicle proceeds in the correct direction on the off-ramp.

Where an off-ramp has two lanes such as indicated by the dotted lines in FIG. 1, a separate series of switches S1', S2 and S3 are provided, and a curb C extends between the lanes for purposes to be described hereinafter. The barrier 4 is extended so as to be operative in both lanes simultaneously. If a wrong-way driver enters either lane, he can not avoid the barrier by switching lanes.

In FIG. 4 there is diagrammatically illustrated a relay system for achieving the operation of the motor M, the alarm A and the warning system W. The lswitches S1, S2 and S3 are illustrated as before. Switches S1', S2 and S3 are provided for the other lane. The operation for each side is identical to that previously described except that the motor M, alarm A and warning system W can be energized either through a second set of contacts R3B of the relay R3 or a corresponding set of contacts R3B' of the relay R3. Thus the contacts R3B and R3B' are both interconnected by -a lead L5 and to the motor M, alarm A and warning W. Thus should a wrong-way driver enter one of the lanes the barrier etc. will be operateed as before. However, `after the wrong-way driver has entered one lane, the passage of another vehicle in the correct direction from the companion lane will not lower the barrier 4 because the reset switches S1 and S1 only reset their corresponding relays. The curb C prevents a right way driver from resetting the barrier by change of lanes.

The inventor claims:

1. In a system for inhibiting movement of a wrong-way driver along a one-way lane that intersects a two-way street: means forming a recess in the lane at a place spaced substantially from the intersection; a barrier; means retractably mounting the barrier in the recess for movement from a position beneath the level of the lane to an elevated operative position; said barrier having means for disabling a vehicle engaging the barrier from the direction of the intersection; said retractable mounting means permitting said barrier to yield upon engagement from the other direction; means mounted adjacent the lane between the intersection and said barrier for sensing the direction of movement of vehicles; said sensing means being operable independently ofthe speed of said vehicles; operating means controlled by said sensing means for elevating said barrier and retracting the barrier in accordance with the direction of movement of such vehicles.

2. The combination as set forth in claim 1 together with a plurality of warning alarm elements operatively associated with said operating means.

3. In a system for -inhibiting movement of a wrongway driver along a one-way lane that intersects a twoway street: means forming a recess in the lane at a place spaced substanially from the intersection; a barrier designed to disable vehicles engaging the barrier only from one direction; means -retractably mounting the barrier in the recess for movement from a position entirely at or beneath the level of the lane to an elevated position in which the barrier will disable the vehicles moving in the wrong direction, comprising .a series of three two state sensing elements normally in one. state and switched to a second state `by passage of a vehicle, and mounted Iat the lane between the intersection and said barrier with the rst sensing element closest to the street, the third sensing element closest to the barrier, and the second sensing element in between the others; a pair of two state logic elements each normally in one state; means dependent upon said second sensing element being in its second state for switching one of said logic elements from its one state to its second state; means holding said one logic element in its second state and dependent upon said rst sensing element being in its one state; means dependent upon the third sensing element being in its second state and upon said one logic element being in its second state for switching the other of said logic elements from its one state to its second state; means holding said second logic element in its second state and dependent upon said iirst sensing element being in its one state; `and means elevating said barrier when said other logic element is in its other state; said barrier normally returning to a retracted position.

4. In asystem for inhibiting movement of a wrongway driver along a one-way lane that intersects -a twoway street: means forming ya recess in the lane at a place spaced substantially from the intersection; a barrier designed to disable vehicles engaging the barrier only from one direction; means retractably mountingV the barrier in the recess for movement from a position entirely at or beneath the level of the lane to Ian elevated position in which the barrier will disable the vehicles moving in the wrong direction, comprising a series of three pressure switches located in the lane between the barrier and the street, for operation by a passing vehicle, the rst switch being normally closed and closest the street, the second and third switches being normally open, with the second switch between the first and third switches; a conditioning relay operated by the second switch and held when said rst switch is closed; an operating relay operated by the conditioning relay and said third switch, said operating relay also being held when said first switch is closed; and electrically energizable means operated by said operating relay for elevating said barrier; said barrier normally returning to a retracted position.

5. ln a system for inhibiting movement of a wrongway driver along adjoining one-way lanes that intersect a street: means forming recesses in the lanes at a place spaced substantially from the intersection; barrier means designed to disable vehicles engaging the barrier means only from one direction; means retractably mounting the barrier means in the recesses for movement from positions entirely at or beneath the level of the lanes to elevated positions in which the barrier means will disable the vehicles moving in the wrong direction; means mounted adjacent the lanes between the intersection and the barrier means for sensing the direction of movement of vehicles in `all lanes, comprising for each lane, a series of three two state sensing elements normally in one state and switched to a second state by passage of a vehicle, and mounted at the lane between the intersection and said barrier means with the first sensing element closest to the street, the third sensing element closest to the barrier means, land the second sensing element in between the others; a pair of two state logic elements each normally in one state; means dependent upon said second sensing element 4being in its second state for switching one of said logic elements from its one state to its second state; means holding said one logic element in its second state and dependent upon said first sensing element being in its one state; means dependent upon the third sensing element being in its second state and upon said one logic element being in its second state for switching the other of said logic elements from its one state to its second state; means holding said second logic element in its second state and dependent upon said first sensing element being in its one state; and means elevating all the barrier means when the said other logic element for any of said lanes is in its said other state; said barrier means normally returning to a retracted position.

6. In a system for inhibiting movement of a wrongway driver along adjoining one-way lanes that intersect a street: means forming recesses in the lanes at a place spaced substantially from the intersection; barrier means designed to disable vehicles engaging the barrier means only from one direction; means retractably mounting the barrier means in the recesses for movement from positions entirely at or beneath the level of the lanes to elevated positions in which the barrier means will disable the vehicles moving in the wrong direction; means mounted adjacent the lanes between the intersection and the barrier means for sensing the direction of movement of vehicles in all lanes, comprising for each lane, a series of three pressure switches located in the lane between the `barrier means and the street, for operation by a passing vehicle, the iirst switch being normally closed and closest the street, the second and third switches being normally open, with the second switch between the iirst and third switches; a conditioning relay operated by the second switch :and held when said first switch is closed; an operating relay operated by the conditioning relay and said third switch, said operating relay also being held when said iirst switch is closed; and electrically energizable means operated by the operating relay of any of said lanes for elevating all of said barrier means; said barrier means normally returning to retracted positions.

7. In a warning system: a one-way driving lane; electrically operated means for warning wrong-way drivers of the improper movement along said one-way driving lane; a series of three two state sensing elements normally in one .state and switched to -a second state by passage of a vehicle, and mounted at said one-way driving lane in spaced relationship with `the first, second and third sensing elements positioned to be operated successively by movement of a vehicle in the wrong direction along said lane; a pair of two state logic elements each normally in one state; means dependent upon said second sensing element being in its second state for switching one of said logic elements from its one state to its second state; means holding said one logic element in its 4second state and dependent upon said first sensing element being in its one state; means dependent upon the third sensing element -being in its second state and upon said one logic element being in its second state for switching the other of said logic elements from its one state to its second state; means holding said second logic element in its second state and dependent upon said first sensing element being in its one state; and means operating said warning means only when said other logic element is in its other state.

8. In a warning system: a one-Way driving lane; a series of three pressure switches located in said one-way driving lane for operation by a passing vehicle, the first switch being normally closed, the second and third switches being normally open with the second switch between the first and third switches; the first, second and third switches being spaced to be operated successively by movement of a vehicle in the Wrong direction along said lane; a conditioning relay operated by the second switch and held when said first switch is closed; an operating relay operated by the conditioning relay and said third switch, said operating relay also being held when said first switch is closed; and electrically energizable means operated by said operating relay for warning a wrong way driver of improper direction of travel relative to the said one-way driving lane.

9. In a warning system: a plurality of parallel one-way driving lanes; each of said lanes having a series of three pressure switches located in said one-way driving lane for operation by a passing vehicle, the first switch being normally closed, the second and third switches being normally open with the second switch -between the first and third switches; the iirst, second and third switches being spaced to be operated successively by movement of a vehicle in the wrong direction along said lane; a conditioning relay operated by the second switch and held when said first switch is closed; an operating relay operated by the conditioning relay and said third switch, said operating relay also being held when said first switch is closed; and electrically energizable means operated by the operating relay of any of said lanes for warning a wrong way driver of improper direction of travel relative to the said one-way driving lanes.

References Cited UNITED STATES PATENTS 2,313,627 3/1943 Cooper 340-39 FOREIGN PATENTS 16,011 11/1912 France. 313,371 6/1929 Great Britain. 358,620 10/1931 Great Britain.

NEIL C. READ, Primary Examiner.

'I'. B. HABECKER, Assistant Examiner.l 

1. IN A SYSTEM FOR INHIBITING MOVEMENT OF A WRONG-WAY DRIVER ALONG A ONE-WAY LANE THAT INTERSECTS A TWO-WAY STREET: MEANS FORMING A RECESS IN THE LANE AT A PLACE SPACED SUBSTANTIALLY FROM THE INTERSECTION ; A BARRIER; MEANS RETRACTABLY MOUNTING THE BARRIER IN THE RECESS FOR MOVEMENT FROM A POSITION BENEATH THE LEVEL OF THE LANE TO AN ELEVATED OPERATIVE POSITION; SAID BARRIER HAVING MEANS FOR DISABLING A VEHICLE ENGAGING THE BARRIER FROM THE DIRECTION OF THE INTERSECTION; SAID RETRACTABLE MOUNTING MEANS PERMITTING SAID BARRIER TO YIELD UPON ENGAGEMENT FROM THE OTHER DIRECTION; MEANS MOUNTED ADJACENT THE LANE BETWEEN THE INTERSECTION AND SAID BARRIER FOR SENSING THE DIRECTION OF MOVEMENT OF VEHICLES; SAID SENSING MEANS BEING OPERABLE INDEPENDENTLY OF THE SPEED OF SAID VEHICLES; OPERATING MEANS CONTROLLED BY SAID SENSING MEANS FOR ELEVATING SAID BARRIER AND RETRACTING THE BARRIER IN ACCORDANCE WITH THE DIRECTION OF MOVEMENT OF SUCH VEHICLES. 